Capacity.cpp

// C++ program to illustrate the
// capacity function in vector
#include <iostream>
#include <vector>

using namespace std;

void main() {
	vector<int> g1{ 2,4,6,8,10 };

	cout << "Size : " << g1.size();
	cout << "\nCapacity : " << g1.capacity();
	cout << "\nMax_Size : " << g1.max_size();

	// resizes the vector size to 4
	g1.resize(4);

	// prints the vector size after resize()
	cout << "\nSize : " << g1.size();

	// checks if the vector is empty or not
	if (g1.empty() == false)
		cout << "\nVector is not empty";
	else
		cout << "\nVector is empty";

	// Shrinks the vector
	g1.shrink_to_fit();
	cout << "\nVector elements are: ";
	for (auto it = g1.begin(); it != g1.end(); it++)
		cout << *it << " ";

}

/*
Output:
Size : 5
Capacity : 5
Max_Size : 1073741823
Size : 4
Vector is not empty
Vector elements are: 2 4 6 8
*/

/*
size() – Returns the number of elements in the vector.
max_size() – Returns the maximum number of elements that the vector can hold.
capacity() – Returns the size of the storage space currently allocated to the vector expressed as number of elements.
resize(n) – Resizes the container so that it contains ‘n’ elements.
empty() – Returns whether the container is empty.
shrink_to_fit() – Reduces the capacity of the container to fit its size and destroys all elements beyond the capacity.
reserve() – Requests that the vector capacity be at least enough to contain n elements.
*/